UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK.
Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI 48202, USA.
Cells. 2024 Jun 25;13(13):1100. doi: 10.3390/cells13131100.
The retinal pigment epithelium (RPE) is an essential component of the retina that plays multiple roles required to support visual function. These include light onset- and circadian rhythm-dependent tasks, such as daily phagocytosis of photoreceptor outer segments. Mitochondria provide energy to the highly specialized and energy-dependent RPE. In this study, we examined the positioning of mitochondria and how this is influenced by the onset of light. We identified a population of mitochondria that are tethered to the basal plasma membrane pre- and post-light onset. Following light onset, mitochondria redistributed apically and interacted with melanosomes and phagosomes. In a choroideremia mouse model that has regions of the RPE with disrupted or lost infolding of the plasma membrane, the positionings of only the non-tethered mitochondria were affected. This provides evidence that the tethering of mitochondria to the plasma membrane plays an important role that is maintained under these disease conditions. Our work shows that there are subpopulations of RPE mitochondria based on their positioning after light onset. It is likely they play distinct roles in the RPE that are needed to fulfil the changing cellular demands throughout the day.
视网膜色素上皮 (RPE) 是视网膜的重要组成部分，它具有多种功能，包括支持视觉功能所需的光起始和昼夜节律依赖的任务，如每天吞噬光感受器外节。线粒体为高度特化和能量依赖的 RPE 提供能量。在这项研究中，我们研究了线粒体的定位以及光起始如何影响其定位。我们鉴定了一群在光起始前后与基底质膜相连的线粒体。光起始后，线粒体重新分布到顶端，并与黑素体和吞噬体相互作用。在具有 RPE 质膜内陷中断或缺失的脉络膜黑变病小鼠模型中，只有非固定化线粒体的定位受到影响。这表明线粒体与质膜的固定化在这些疾病状态下起着重要作用。我们的工作表明，RPE 线粒体根据光起始后的定位存在亚群。它们很可能在 RPE 中发挥不同的作用，以满足细胞在一天中的不同需求。
